Chlorhexidine (Rose, Swain, J. Chem. Soc. 1956, 4422, U.S. Pat. No. 2,684,924) and its salts, including the gluconate salt (CHG), is well known as a water soluble topical antimicrobial (G. E. Davies et al. Brit. J. Pharmacol. 9, 192 (1954) and D. M. Foulkes, J. Peridont. Res. 8, Suppl. 12., 55-60 (1973)). Numerous compositions containing CHG as an active ingredient to fight microbial infection after surgery or during wound healing are known. Chlorhexidine and its salts are effective against a wide range of Gram-positive and Gram-negative bacteria. It is also effective against Proteus and against some fungi and viruses. CHG is currently marketed in compositions sold and directly applied at a 4% concentration level e.g., HIBICLENS.TM. (commercially available from Stuart Pharmaceuticals),to achieve an antimicrobial effect.
The combination of an alcohol and CHG is known. For example, the combination of CHG and denatured alcohol containing the denaturant brucine sulfate is known as a composition useful in surgical scrub applications. The combination of a bisbiguanide such as CHG, and an alcohol such as isopropanol or ethanol is also known. See U.S. Pat. Nos. 5,164,107 or 5,089,205. Four percent of isopropanol was added to stock solutions of CHG in the '107 disclosure to prevent the contamination of the stock solution with species of Pseudomonas.
Solutions of 0.5% CHG with 70% isopropanol, and 1.0% CHG with 50% ethanol, were described as skin-disinfectant (see Beeuwkes et al., Acta Therapeutica 11 (1985) pp. 445-451, and Beeuwkes et al., Journal of Hospital Infection 8 (1986) pp. 200-202).
The present invention is a cleanser system of CHG and a denatured alcohol, which is highly effective as an antimicrobial surgical scrub or hand wash composition and is more effective than the prior art compositions.